Vascular disease may include an impairment of a patient's blood flow or an irregularity of a patient's circulatory system. For example, the impairment may include blood flow not being sufficient for meeting tissue demand for blood. This insufficient blood flow may lead to impairment of tissue function or patient death. For example, coronary artery disease (CHD) may impair cardiac function, leading to cardiac arrest or death. As another example, peripheral artery disease (PAD) may entail reduced blood flow to limbs, which may cause loss of function of the limb. Clinical techniques for assessing vascular disease may include observing functional compromise due to disease (e.g., percent stenosis, fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), coronary flow reserve (CFR), etc.) or a perfusion deficit (e.g., assessed by single-photon emission computed tomography (SPECT), (positron emission tomography (PET), ultrasound, magnetic resonance (MR) perfusion, computed tomography (CT) perfusion, etc.). However, these clinical tools may be limited because: 1) a diseased vessel may not cause a significant perfusion deficit (e.g., small vessels); 2) in patients with multivessel disease, there may be no clear way to associate a specific vessel disease with a perfusion deficit, except through a population-based vessel territory map; 3) a detected perfusion deficit may not have significant impact on cardiac or muscle function (e.g., depending on location/size of the deficit); or 4) a treatment to revascularize the vascular (e.g., coronary) lumen (e.g., percutaneous coronary intervention (PCI), angioplasty, coronary artery bypass grafting (CABG)) may not restore sufficient blood supply to the heart/muscle to correct an impacted cardiac/muscle function.
Thus, a desire exists to better assess the impact of vascular disease, for example, by determining how vascular disease may impact tissue or organ function and/or how vascular disease may affect a risk of patient death. Furthermore, a desire exists to assess whether a treatment may improve tissue or organ function and/or decrease a likelihood of patient death.
The foregoing general description and the following detailed description are directed to overcoming one or more of the challenges described above. The general description and detailed description are exemplary and explanatory only and are not restrictive of the disclosure.